Plants become aware that fall is approaching well before humans. For those of us who work with plants, we think of fall as beginning well before coffee shops start offering pumpkin spice lattes. Best to get started on your fall gardening tasks immediately!
Get leaves up as soon as they start falling
The process of leaves falling from trees is called abscission and it begins before the leaf actually falls from the tree, happening in three steps: remobilization, protective layer formation, and detachment. During remobilization, the tree extracts nutrients from chlorophyll, degrading it, and causing the leaf to change color by leaving carotenoids (orange, red, and yellow plant pigments) in place but destroying the chlorophyll. Nitrogen in particular is often bound up in chlorophyll and the tree needs that nitrogen to get through the winter.
There are two common misconceptions among gardeners: 1. Plants don’t need nitrogen in winter and any nitrogen they get will cause them to put on new growth and become vulnerable to winter cold; 2. Leaves allowed to decompose in winter will become a good source of nitrogen in the spring.
First, though high nitrogen inorganic fertilizer with no time release component in late summer or early fall may cause a burst of new growth in some circumstances, the concern is usually overblown. Winters in Memphis tend to be mild and approach gradually, and plants need nitrogen in varying amounts year round. Second, as we learned when looking at the process of abscission, much of the nitrogen is sucked out of leaves by the plant before leaf drop.
Accordingly, allowing leaves to sit under trees and around shrubs all winter, year after year, as they do in forests, is not good for the plants. To see what happens in the “natural state,” walk through The Old Forest in Overton Park and notice how a large percentage of plants in an actual forest are in various states of deterioration and decay. Forests survive, often, more by their prolific seed drop rather than because conditions are ideal for individual plants. New plants are ever replacing old plants, giving the illusion of consistency.
So, start getting up leaves as soon as they start falling! Blow or rake leaves out of beds regularly, maybe onto your turf grass, and then run over them with a lawn mower, before the leaf volume gets so great that it will choke your mower. Then bag the shredded leaves and place them curbside for municipal pickup (shredding them first will reduce the number of bags needed tremendously and speed their decomposition in a landfill) or put them in your compost bin. Remember, though leaves alone are poor sources of nitrogen, composted leaf mulch, mixed with other compost, can be good spring fertilizer or a component for a custom soil mix.
Allowing leaves to accumulate excessively on top of the lawn will create the perfect breeding ground for fungal problems. Raise the mower blades to 3-4 inches in late summer and let the mower suck up some leaves and leave a small amount of shredded leaves in the turf.
Plant fall annuals for color
It would be unwise to plant an entire yard in annuals, given the expense. But, every yard should have designated spots for seasonal color. Some of the best annuals for planting in the fall include pansies, violas, mums, snapdragons, swiss chard, and kale. Urban Earth Garden Center has a full selection in stock right now. To see more of what’s in stock, check out our slideshows on our facebook page, Urban Earth by Greg Touliatos.
To really learn about fall color, join us for a free class on the subject (“Fall Annuals and Fall Bulbs for Your Garden”) by David Levy, Greg Touliatos, and John Jennings on Saturday, October 14, 2017 at 1pm.
Put down a granular pre-emergent
Put down a granular pre-emergent in both the spring and fall to stop weed seed from germinating. We like Hi-Yield Turf & Ornamental Weed & Grass Stopper Containing Dimension. One bag will cover up to 3,500 square feet of planting beds or up to 5,000 square feet of turf. Though it is not a cure-all, it will form a chemical barrier that will prevent a large percentage of weed seed from germinating and becoming fall annual weeds. Preen is the most widely known pre-emergent among consumers but we like this product better.
Put down seed for cool season plants
Apply fescue seed, winter rye seed, or “fall cover crop” mixes to your turf in September and October for best results.
Fescue is often described as a shade grass but a more accurate description is a cool season grass that does well under the canopies of deciduous trees. Zoysia and Bermuda are warm season grasses, meaning that they engage in photosynthesis in the spring and summer and go dormant when temperatures drop. In contrast, cool season grasses, like fescue, engage in photosynthesis, coming alive, after leaf drop. The fact that fescue is not a “shade grass” is important because it would not do well under the canopies of evergreen trees. (Note: Creeping red fescue is a genuine shade grass but is not recommended because it has zero tread tolerance; even a squirrel walking across it will kill it, the reason we don’t carry the “deep shade” fescue mixes some other garden centers carry.)
Also, remember that fescue is only barely tolerant of our heat. Hence, it thins in late summer and needs to be over-seeded at least once per year, every fall, and preferably again in late winter, around the time crocuses start coming up or shortly thereafter, to create a lush look. How to install fescue is beyond the scope of this article but come see us and we will be happy to explain it!
Fall cover crops are plants that do well in cooler temperatures and are special because of their nitrogen fixing qualities. They are generally, with some exceptions, annuals, meaning they won’t come back again after their season completes.
By nitrogen fixing qualities, we mean that they have a symbiotic relationship with certain bacteria in the soil that allows the plants to pull nitrogen directly from the ambient air for their benefit and the benefit of plants around them, releasing the nutrients into the soil when they die at the end of their season. These plants include legumes like red clover (annual) or durana white clover (perennial), both of which we carry as stand-alone products and in mixes. For a better understanding of how to use fall cover crops to improve the look and health of your turf, please visit our store.
Fall is the time to plant bulbs like daffodils, crocus, and tulips for winter to spring beauty. This year, we will be receiving our bulb order from Devroomen, one of the best suppliers of bulbs in the world, in the first or second week of October. Although you can install bulbs well into January or even, in some cases, February, if you wait too long after they arrive at our store to buy them, you will have fewer choices. They go quickly!
This author likes to install bulbs the Friday, Saturday, or Sunday after Thanksgiving as a family activity. Installing bulbs too early can mean that they start coming up too early, making the new growth vulnerable to the destructive effects of a hard freeze. After Thanksgiving, the chances of a false spring are much less.
Generally, in Memphis, daffodils and crocuses are perennials, meaning that they will come back every year, while tulips are annuals. Though daffodils and crocuses are technically perennials here, they have an ephemeral nature in that they don’t seem to come back every year. In my experience, in any given year, 80% of my daffodils will pop up and bloom, but it won’t be the same 80% each year. Crocuses are similar in that regard.
Crocuses, my favorite bulbs, are often overlooked as options by gardeners. But, they do well under the canopies of trees, whereas daffodils really need more sunlight to come back up again in future years. Further, crocuses come up earlier than most everything else, often seen pushing up through ice and snow as a beautiful harbinger of spring. Though the metaphor may be nearly cliche, gardeners are like wine drinkers. New wine drinkers like sweet and fruity wines, like a pinot grigiot, sauvignon blanc, or even an after dinner sweet port. But, as they mature in their appreciation of wine, they move onto the cabernets and the merlots.
Bulbs are like that in that new gardeners tend to gravitate towards the tulips, mere annuals in our climate, but bright and showy, while crocuses are generally something appreciated by more experienced gardeners for their subtlety.
One thing to keep in mind about bulbs is that the photosynthates absorbed by the plants coming up from the bulbs this year determine their success in the following year. So, if you plant them in too little sunlight, they will likely come up fine the first year but will perform poorly, if at all, the following year. For the same reason, it is important not to cut your plants back after the blooms are spent until the plants themselves begin to deteriorate to give the leaves as much time as possible to create and store photosynthates (a nutrient that can only be made when light is being absorbed) to ensure a good outcome for the next year.
Remember, all bulbs require a certain number of hours of chill time in order to be successful. All of our bulbs come pre-chilled. It is for this reason, perhaps, that after mild winters in Memphis, fewer daffodils and crocuses come up but come back in subsequent cooler years.
Between the time that you buy bulbs and the time you plant them, keep them in a paper sack in a cool dark place, ideally at a temperature below 70 degrees Fahrenheit.
Plant trees and shrubs
Although good gardeners can plant trees and woody shrubs any time of the year, there is no question that the best time to do so in Memphis is the fall. Temperatures are moderating, slowing soil evaporation, and the rainy season is beginning, giving new plants, which always begin with shallow root systems, a much better chance of survival and allowing them to develop a wide and deep root system before Memphis’s drought period in July and August. Further, many plants go into dormancy, a self-protective mode where the focus of their growth shifts from their canopies above ground to their root systems below ground, meaning that they develop root systems faster in the fall than they would any other time of the year.
But beware, a well-managed nursery should not be too soft with its plants in winter. All plant nurseries wrap their greenhouses in plastic in winter, but good nursery managers are also careful to properly harden their plants off. Tender new canopy growth in plants is a point of vulnerability when a freeze hits. So, if you buy plants from a garden center that has kept its greenhouses too warm, causing them to put on lots of pretty new growth, you may have a dead plant a few weeks after you put it in the ground. Hardening off plants and keeping them hardened off until winter has ended is an art, a process
Greg Touliatos personally supervises and monitors at Urban Earth Garden Center, entrusting it to no one else.
For ideas on trees to plant in your yard, see the article, “Best Trees for Memphis,” or, better yet, come talk to us in the store and we can look at the options together. For best results, email the street address and photos of the area where you want to plant ahead of time to firstname.lastname@example.org. If you there is a plant you want but think we might not have in stock, email us to request it. Be sure to put “Plant Request” in the subject line and we will confirm receipt of your email and let you know if and when we are able to find it, by email.
Transplant trees and woody shrubs
For the same reason fall is the best time to install woody plants in Memphis, it is really the only time to transplant woody plants in Memphis. The very act of transplanting causes significant damage to a plant’s root system, reducing its ability to take up moisture and nutrients from the soil. Transplanting is too complicated in scope to address this article, but please visit us for advice on transplanting.
In particular, this author recommends that you use Fertilome Root Stimulator. Fertilome Root Stimulator contains auxins, plant hormones that help stimulate new root development, and other nutrients needed for plants with damaged root systems. Be careful using other fertilizers when transplanting, because recently transplanted specimen are particularly vulnerable to burn from excessive fertilization.
Apply time release 12-6-6 fertilizer in spring and fall, like the Hi-Yield Growers Special that we carry, or an organic alternative like Happy Frog by Fox Farm. Apply soil sulfur to all of your woody plants, except boxwoods, especially azaleas, hydrangeas, and hollies. (Note: If you are regularly using Happy Frog Fertilizer for Acid Loving Plants there is no need to apply soil sulfur, in my view.) Apply lime to boxwoods every other year or so to raise the ph, a measure of soil alkalinity or acidity, since boxwoods are about the only plant commonly used in ornamental beds in Memphis that likes a more alkaline soil, preferring a slightly higher ph than other woody plants. Let us guide you in the specifics of applying these products when you visit.
Many gardeners are shy about pruning or trimming plants too late in the year. Pruning and trimming can stimulate new growth, and as already explained above, new growth makes the entire plant more vulnerable to cold damage. But, if you’re in the garden already, in Memphis, it won’t hurt and may very likely help to do a little careful pruning. At least prune any deadwood out of your woody plants, selectively thin plants with dense growth by removing branches, and prune a third of the canopies of your roses back in the fall (You will prune another third of the canopy of your roses back right after Christmas, before the winter winds get especially strong). Do not do any wholesale shearing with a power trimmer to shape as this will definitely stimulate new growth!
When you prune, always use high quality bypass pruners and be sure to disinfect your pruners between plants with a 10% solution of bleach to prevent disease spread. We carry the industry gold standard for bypass pruners, Felco, but we also carry less expensive but still excellent models by Corona and Tierra Pro. Anvil pruners, which we do not sell at Urban Earth, tend to mash the branches rather than cleanly cutting through them, whereas bypass pruners make healthy cuts with fewer entrance points for plant disease. (I have yet to come across a single good reason for a gardener to own a pair of anvil pruners.) Make sure your pruners are sharp too for the cleanest cuts. If you’re not sure about the pruners you currently own, come see us for guidance and advice in learning to maintain them.
Fall is a great time to go full on Martha Stewart! It’s easy to cut flowers in the spring and summer and stick them in water. But, fall both requires and allows for more creativity. For more information, google “creating fall centerpieces for tables” and a wealth of information will come up. One of our employees, Martha “Martha Stewart” Garriott, is particularly talented and will be happy to help you pick out the perfect vessel and find seasonally appropriate cuttings and elements to complete the centerpiece.
Fall is a great time to read, study, and sharpen your knowledge as a gardener. And, there is no better
place than Urban Earth Garden Center to help you along this journey. We have a clever selection of books, knowledgeable employees who give good advice, a regular schedule of free classes in our education annex, outside speakers, and hands on assistance and guidance. Follow us on Facebook to find our seminar schedule or look for it in our blog section, updated a few times each year; read our blog; subscribe to and read our emailed newsletter by emailing email@example.com and requesting that you be added or messaging us on our fb page; and email me with questions and photos (firstname.lastname@example.org).
The author, John Jennings has been manager of Urban Earth Garden Center since June 1, 2016. Before that he was a self-employed landscaper for 8 years, having previously worked as both a real estate lawyer and a drug counselor in previous lives. He grew up in the South Carolina low country, learning to garden in the fertile soil of Copes Island, a small barrier island near Beaufort, in Jasper County, the famed land of Pat Conroy. He was taught the basics of planting by his step-father, Wade, his mother, Melissa, and his father, Karl. Though both of his parents grew up in Memphis, and he spent vacations visiting his maternal grandparents, Richard and Diana Allen in Memphis, he did not become a resident of the city until he finished college in 1994. He left South Carolina at the age of 14 to attend The McCallie School for Boys, in Chattanooga, Tennessee, graduating in 1990, before getting a degree in English from the University of Richmond, in Virgina,in 1994, finally graduating from the University of Memphis Law School in 1997. He has a 10 year old son named Henry. If you read this blog entry, please email the author at email@example.com and let him know what you think.
THE BEST TREES FOR MEMPHIS
(AN ODE TO COLUMNAR DECIDUOUS TREES)
Though a good horticulturalist can be successful planting any time of the year, the best time to plant trees and other woody plants in the Memphis area is in the fall. So, it’s time to start contemplating what you’re going to plant this fall! (This is the first of a series of blog posts I’ll be doing on fall gardening activities over the next few months.)
Trees are categorized in many ways. Aesthetically, trees are most often categorized by size, shape, and whether they are deciduous (meaning they lose their leaves in winter) or evergreen (meaning they keep leaves year round). The size categories are usually small, medium, or large, defined best here, https://www.arborday.org/trees/righttreeandplace/size.cfm, while canopy shape is defined best here: https://extension.tennessee.edu/publications/Documents/SP531.pdf. The tree sizes and shape I advocate most for in urban environments, which usually have smaller yards, are small to medium sized trees with columnar shaped (also called fastigiated) canopies.
Columnar trees have a strong vertical form and are often six feet or less in width. The most well-known columnar tree forms are probably arborvitae and Italian cypress, both commonly associated with Mediterranean landscapes but widely used in Memphis. For example, Presbyterian Day School has a row of small arborvitae, about 8 feet tall, on the south end of one of its playing fields bordering Central Avenue. Then, there is a row of 3 very tall Italian cypresses, over 30 feet, in midtown on Evergreen, a couple of blocks north of India Palace Restaurant. These two examples are both evergreen.
But, lesser known, and I think under-utilized until the last few years in Memphis are columnar deciduous trees. We often think only of deciduous trees as large shade trees, except perhaps for Japanese and other maples or the widely over-planted crepe myrtles. Customers rarely specifically request a columnar deciduous tree at our nursery. In fact, just as new wine drinkers often prefer sweet white wines before maturing into cabernets and merlots, inexperienced gardeners gravitate towards things that are covered in blooms part of the year or evergreen, preferably both, fearing the bareness of deciduous plants in winter and not appreciating the texture of mere leaves without flowers.
One big advantage of deciduous columnar trees over evergreens like arborvitae and Italian cypress is that they tend to have fewer problems. The evergreens prefer the subtly different Mediterranean climate rather than ours, are sensitive to both under-watering and over-watering, and too often get bag worms and other pests, particularly in early summer. In contrast, well-planted deciduous columnars are relatively maintenance and pest free, needing only the occasional pruning of dead branches. Without leaves in winter, a sudden ice storm is less likely to damage them too. Most importantly, as a gardener matures in her appreciation of the life cycle of plants, she comes to appreciate the changing shape and color of leaves over the course of spring, summer, and fall, and the architecture of bare branches in winter.
He who marvels at the beauty of the world in summer will find equal cause for wonder and admiration in winter…. In winter the stars seem to have rekindled their fires, the moon achieves a fuller triumph, and the heavens wear a look of a more exalted simplicity. ~John Burroughs
So, increasingly, the landscape industry and home owners are realizing that medium and small deciduous trees in general, including columnar cultivars, are better alternatives than columnar evergreens. Moreover, they are realizing that smaller trees are better for the close confines of modern urban environments than the old standard unimproved shade trees like oaks, elms, gingkoes, and tulip poplars that were widely planted in Memphis during the twentieth century. Indeed, if you have ever had to contend with a large old specimen of a deciduous shade tree too close to your home, you know how challenging they can be. The roots can rip apart foundations and sewer pipes. Leaf removal under the canopies of large old deciduous trees in the fall can be an enormous undertaking. And, worst of all, falling limbs or entire falling trees, weighing tens of thousands of pounds, can destroy property and cause human injury or death. To make matters worse, tree removal of a large deciduous tree that has been diagnosed as too unsafe to keep in place, can cost $15,000 or more.
Consider, for example, a mature oak tree, inexplicably planted 15 feet from the rear of an east-facing home. The tree has been diagnosed with an incurable fungal problem, its roots have largely rotted, and its leaves are only green because of stored photosynthates. It remains erect only because it weighs 70,000 pounds and is like a nail whose point has been tapped into the ground. Eventually, because this is Memphis, a straight-line wind will come along from the west, push the tree over, and flatten the home, destroying it and everything in it. A wise homeowner, faced with this information may feel they have no choice but to pay to remove it at a cost of as much as 10% or more of the home’s value, enough money to buy a new car or increase the size of the home. Likely, this tree was not “planted” but rather was a volunteer, allowed, maybe even encouraged by a new homeowner decades before, a homeowner who likely felt very proud that he had not had to pay for it, regarding others who had designed intentional landscapes as spendthrifts.
But then, there are those who over-react to this problem, removing all trees from their property, leaving only foundation shrubbery and turf grass, with no shade, like the homes in new mid to low grade subdivisions. This approach has its problems too. There is no shade without trees so more energy is needed to cool the home in the summer and the benefit of deciduous trees that mitigate carbon emissions is entirely lost. Further, for whatever reason, humans find the close proximity of trees comforting. They have an inherent attraction for us and we do not find a landscape wholly devoid of them attractive or as appealing as a yard with one or more well-placed trees on it.
Hence, the arbor market is now producing more manageable small and medium-sized columnar cultivars of old standbys. They tuck nicely into courtyards, make for beautiful allees, and form inspiring focal points in corner beds. For greater impact they can even be clustered in trios! Here are some of my favorites from our growers:
Columnar European Hornbeam (Carpinus betulus fastigiata) has been around for a while, the Frans Fontaine cultivar of columnar European hornbeam being my favorite of the various cultivars (a cultivar is a variety of tree discovered by a grower deliberately looking for variations within a population of trees and then propagating, usually by cuttings, that tree because of its atypical but desired qualities.) The ‘Frans Fontaine’ cultivar tends to get about 25 feet tall and 6 feet wide, tucking into the corner of a foundation bed nicely or making a nice focal point in a larger bed. They also look great in a formal row. I first became aware of this tree when the Dixon Garden, under the direction of Dale Skaggs, planted an allee (a walkway or avenue lined on both sides with trees) of them a few years ago. With alternate oblong-ovate leaves with rounded base and acute tip, pale green in spring, dark green in summer, and pale yellow in the fall, the canopy forms a dense oval of overlapping leaves that flutter in breezes and come across like an impressionist painting from even short distances.
Though ‘Frans Fontaine’ gets larger in other climates, in our climate it tends to be more restrained, seldom getting much larger than 25 feet tall and 6 feet wide. Unusually, the tree is tolerant of extreme pruning, some horticulturalists pruning the limbs all the way back to the trunk once each year to keep it even narrower than it already is. It is not infrequently used as a screen or hedge, similar to how english hornbeams are used at one of Martha Stewart’s homes, as described here:
Goldspire Ginkgo (Ginkgo biloba ‘Blagon’) is a new cultivar of an old favorite. Ginkgos have long been regarded as the oldest species in continuous existence on the planet, in either kingdom, with some fossils of ginkgo leaves as much as 270 million years old. They have unique fan shaped leaves leafing out pale green in the spring, darkening, and then turning a striking fluorescent yellow in the fall just before leaf drop. With a large genome of over 10 billion DNA nucleobase letters and over 41,000 predicted genes (the human genome has around 3 billion) the plant has excellent disease resistance and general all-around toughness, having lived through more existential threats than any other plant alive. Though the species can get over 100 feet tall, the Goldspire cultivar (‘Blagon’) tends to be much smaller, 15-20 feet tall and 5-6 feet wide.
Because the cultivar was only introduced in 2010, coming from France, the tree is hard to find. I have sold a handful to customers in Memphis but I don’t know where they are planted. So, just like any new cultivar, it is a risk, since there is not much history to go on. But, given the success of other ginkgo varieties and cultivars, and the benefits of an unusually small cultivar, perfectly sized for tight urban confines, it seems worth the risk. If it proves itself over the next couple of years, it may replace ‘Frans Fontaine’ as my favorite columnar tree. If you want this tree, be sure to email us right away to get on the waiting list for it, as we are only expecting to be able to get a few this fall.
Persian Spire Ironwood (Parrotia persica ‘JL Columnar’) is an even newer cultivar than Goldspire Ginkgo! Discovered by John Lewis of JLPN Nursery in Salem, Oregon in 2013, it is an unusually slow growing ironwood, upright and columnar in shape, topping out at under 15 feet. But, the most unique thing about this tree is its foliage, especially in fall, when it takes on purple, orange, and red hues, sometimes all on the same leaf, and holding onto the tree for quite awhile after the color changes, before fall abscission (leaf drop). Read more about this great new cultivar on the the Pacific Northwest International Society of Arboriculture site: http://pnwisa.org/2017/06/persian-spire-upright-ironwood-parrotia-persica-jl-columnar-p-a-f/
As of this writing, Urban Earth has sold a total of 3 of this plant and has one in stock, all in 15 gallon containers, about 6 feet tall. 2 have been planted at an apartment complex across from Ardent Studios on Madison and one has been planted at a private residence. We hope to get a few more this fall but don’t expect this cultivar to be easy to get for a few years. There is no question that anyone who planted one of these trees this year would have one of the rarest trees planted in Memphis, for at least a few years.
Slender Silhouette Sweetgum (Liquidambar styraciflua ‘Slender Silhouette’) is the tallest of all of the trees referenced in this article. Growing as tall as 60 feet and as wide as four feet, it more commonly tops out at 50 feet with a width of 3 feet. It is also the quickest growing. Though it is used in landscapes in Memphis in a variety of ways, one of the best ways I have seen it used is as a corner piece to soften the edge of a two story home in Germantown. Read more about this tree here: http://www.hortmag.com/plants/plants-we-love/slender-silhouette-sweetgum
Lindsey’s Skyward Bald Cypress (Taxodium distichum ‘Lindsey’s Skyward’) has been around long enough, at least 16 years, to prove itself to be a great success in the Memphis area. Though it is a conifer, it is, in fact, deciduous, but tolerating wet feet better than most. A dwarf, it gets up to 20 feet tall and 6 feet wide. A truly lovely tree, though this author does not have much experience with it, it is one of Greg Touliatos’s favorites.
Mushashino Zelkova (Zelkova seratta ‘Musashino’) was named the “2016 Urban Tree of the Year” by the Society of Municipal Arborists. Meant primarily to be a tough street tree, it can also be used, like all columnar trees, as focal points in the landscape, as allees, and as screens. Though too new of a tree to know for sure, it is said that it “has the genetic potential to reach 45 feet in height and 15 feet in width at maturity,” with orange/red leaves in fall, with leaves in an oval shape and serrated at the edges, reminiscent of a hornbeam’s leaves. Read more about this new tree of great promise here: https://www.amerinursery.com/plants/sma-announces-its-2016-urban-tree-of-the-year-zelkova-serrata-musashino/
Regal Prince Oak (Quercus x warei ‘Long’ REGAL PRINCE) is perhaps the fattest of the trees described in this article, though not the tallest, getting up to around 45 feet and 20 feet wide near maturity. The older leaves turn a beautiful red in the fall after the tree has matured for a few years in the landscape. Look here to find a good concise history of this tree, well proven in the Memphis area: https://www.uaex.edu/yard-garden/resource-library/plant-week/quercus-xwarei-oak-regal-prince-01-22-2016.aspx
Arnold Tulip Poplar (Liriodendron tulipefera ‘Arnold’) is an excellent cultivar of our state tree. It is a compact solution for anyone who wants to show their loyalty to Tennessee but has too small of a yard for a full size tulip poplar. Most commonly, you can expect this tree to mature at around 25 feet tall and 8-10 feet wide in the Memphis area, though it might get taller in other parts of the world. Its blooms are yellow-green, tulip shaped, beginning in late spring through the summer.
The author, John Jennings has been manager of Urban Earth Garden Center since June 1, 2016. Before that he was a self-employed landscaper for 8 years, having previously worked as both a real estate lawyer and a drug counselor in previous lives. He grew up in the South Carolina low country, learning to garden in the fertile soil of Copes Island, a small barrier island near Beaufort, in Jasper County, the famed land of Pat Conroy. He was taught the basics of planting by his step-father, Wade, his mother, Melissa, and his father, Karl. Though both of his parents grew up in Memphis, and he spent vacations visiting his maternal grandparents, Richard and Diana Allen in Memphis, he did not become a resident of the city until he finished college in 1994. He left South Carolina at the age of 14 to attend The McCallie School for Boys, in Chattanooga, Tennessee, graduating in 1990, before getting a degree in English from the University of Richmond, in Virgina,in 1994, finally graduating from the University of Memphis Law School in 1997. He has a 10 year old son named Henry.
Posted by John Jennings, Manager
Looking for something really unique to jazz up your poolside, patio, or porch? Can’t find anything just the right color? Are you thinking of building a planter out of wood just so you can paint it yourself but don’t want it to rot? Consider converting a galvanized metal livestock trough into a custom painted metal planter.
Metal livestock troughs can be used in a wide variety of ways. Imagination is your only limitation! This article is about custom painting a metal livestock trough to use as a planter. Of course, it can make an excellent planter, as is, with no painting, provided that holes are punched in the bottom for drainage. But, many prefer a custom color scheme. To achieve the look, we took the following steps:
- Prepare the surface for primer adhesion.
Coat the entire surface with Zep acidic toilet bowl cleaner, let sit for an hour, coat again with Zep acidic toilet bowl cleaner, let sit for two hours, and then rinse off to remove the zinc coating added during the process of galvanization. No paint that we know of, except for a paint sold by Benjamin Moore that only comes in three colors, will adhere to the surface well unless the zinc coating is removed, regardless of what the manufacturer says on the container.
For example, this author first went to a Sherwin-Williams store and the clerk there insisted that their multi-purpose primer would work without first treating the surface. He even showed me where it says right on the container that it will adhere directly to galvanized metal, saying nothing about removing the galvanization first. Alas, against my better judgment, I tried it. None of it adhered, at all, and we had to strip the entire surface and start over.
A gallon of the Zep Commercial Acidic Toilet Bowl Cleaner cost us less than ten dollars and we used about half of it on the approximately 2x2x3 feet trough we painted. At the time of this writing, a 32 ounce bottle is available at Home Depot in midtown Memphis for $4.49 plus sales tax.
The active ingredient in the Zep Toilet Bowl Cleaner is hydrochloric acid. This is the same active ingredient in muriatic acid, but likely in a much lower concentration. Experienced painters or those comfortable with chemicals will likely prefer to use muriatic acid and dilute it themselves but, for consumers, we felt this was a better approach.
Our research also indicated that white vinegar can work, since it too is very acidic, cleaning vinegar in particular, but will take much longer and may not completely remove the coating, leaving spots where paint can come off. Note that if you just want an aged zinc look, rather than painted metal, an application of white vinegar for 20 minutes, followed by a rinse off, might do the trick. But, you’ll want to experiment with a cheaper piece of galvanized metal, like a small trash can before trying it on a more expensive, brand new trough.
Remember to carefully read the safety instructions on the bottle of Zep and follow them. Wear goggles and gloves and reduce exposed skin areas as much as possible. We used disposable latex gloves that offer some resistance to hydrochloric acid but neoprene or plastic might have been better. Do not mix with any other chemicals, being sure in particular to avoid bleach which will combine with it to create a toxic gas, and be sure to keep baking soda on hand to quickly neutralize the acid and wash it off if any gets on you. Do this project outside or in an area with really good ventilation. Keep children and pets away.
- Provide proper drainage for plants.
Punch drainage holes in the bottom of the container with a large nail or other pointed hole punch and a hammer or drill holes with a bit specifically for cutting holes in metal. Be sure to punch holes in the bottom from the outside, with the nail going into the container, to keep the bottom of the surface level. File down any jagged or sharp pieces that might cut you or others.
When you plant, make sure to put some product in the bottom, like gravel or packing peanuts, wrapped in landscape cloth, to keep soil from packing and plugging the holes you created. An excellent solution we currently sell is called “Drainit,” disks that come in a variety of sizes, ranging from $4.99 to $12.99 at the time of this writing. (https://brainchildincorporated.com/)
Most plants need access to moisture all the time, through their root system, but will die if sitting in too much water. Very few plants can handle constant or even nearly constant wet feet. (A few exceptions might include equisetum, Louisiana iris, and papyrus, plants that typically grow in boggy areas or along the edges of bodies of water.)
Be sure to use something like pot feet to raise the planter up enough to preserve drainage and some sort of reinforcement under the trough to provide support. There are many ways of accomplishing this objective, too numerous to list here; just know that if there is no space between container and ground, there is no drainage. Water must have an empty space in which to drain.
- Prime the surface.
Spray the entire surface with Rustoleum Self-Etching Primer. There are likely many types of primer that will work but this is the one that works best of the primers we tested. One can cost $4.76 at the time of this writing at Home Depot in midtown Memphis. We used only one can but ran just a little short, filling the gap with another primer we liked less. We could have used another quarter can or so.
Remember that when you removed the zinc coating, you lost the benefit of galvanization, rust resistance. It is best to coat the entire surface, even the edges of the holes you made for drainage, with both primer and at least two coats of paint to reduce the likelihood of rust.
Allow the primer to dry for 2-24 hours, depending upon temperature and humidity. Dry to the touch is probably good enough. We painted 3 hours after applying the primer on a hot July afternoon.
- Define the lines with tape.
If you are attempting to do a two tone look, like ours, use painters tape or masking tape to define the lines. Unless you are an experienced artist or just painting the entire container a single color, don’t try to free hand it. Make sure the tape is firmly adhered without bubbles along the edges to keep paint from drifting underneath it, distorting what would otherwise be a clean line.
When you go to apply the second color, you will have to remove the first round of tape and apply new tape over the area previously painted. If the first color is not thoroughly dry, the tape may pull it off so don’t be in too much of a hurry to apply the second color. We waited until the following day but it was a hot time of the year in Memphis, July, despite being very humid. You might be able to apply the second color after only a few hours on the same day or you might have to wait 2 or 3 days depending upon the temperature and humidity.
- Paint it.
We used Sherwin-Williams exterior latex enamel. In all likelihood, most paints will work if the surface is prepped and primed properly but we wanted the most durable, easily washable coating possible. We decided that would be an exterior latex enamel and Sherwin-Williams just happened to be the closest most convenient source for us. For this project, we also wanted a shiny, vibrant look to intensify spring and summer color and balance blander winter tones when trees defoliate, warm season grasses tan, and flowers disappear.
We waited two hours after the first coat before applying the second coat, and then applied a 3rd coat the next morning. We repeated the process after removing the first tape and applying new tape to define the field of application for the second color, again applying 3 coats.
- Plant it.
Remember that healthy plants start with good soil. There are many different brands that are good. We are currently selling Fafard’s Ultra Container Mix with Extended Feed, which we like a lot, but we also sometimes sell Dr. Earth, Vortex, Fox Farms, and Happy Frog, all good mixes. There are also lots of recipes online for making your own from bulk ingredients, if you need a lot. Just make sure that the soil is a container/potting mix rather than garden mix. Garden mixes tend to have too much organic matter and are heavier, retaining too much water for containers that may not drain as well as in-ground planting beds.
When planting in containers, choose plants that are hardy for your area to two zones less than your planting zone. Remember that plants in outdoor containers must be cold hardier than plants installed in-ground to survive our winters. For example, Memphis is a Zone 8a (though it used to be classified as 7b). Therefore, any plant you expect to survive our winter will need to be zone 6a or better unless the winter is unusually mild. For obvious reasons, plants in containers just aren’t as well insulated from temperature as plants in-ground.
This project will likely take you about 6-8 hours spread out over a few days. It could be done in one weekend but does not have to all be done at once. It can be a pleasant stress relief to do alone but it can be an even better experience to do it with partners or children. Just be sure to exercise every safety precaution and perhaps use the hydrochloric acid (acidic toilet bowl cleaner in this case) before including a child in the project. As always, don’t be in such a hurry to get to the outcome that you miss out on what you might have gotten from the process. As Pirsig wrote in his book, Zen and the Art of Motorcyle Maintenance, “We’re in such a hurry most of the time we never get much chance to talk. The result is a kind of endless day-to-day shallowness, a monotony that leaves a person wondering years later where all the time went and sorry that it’s all gone. ” Garden projects are the perfect vehicle for connecting with others!
John Jennings, Manager
“We are beginning to learn that our brains are hardwired to react positively to water and that being near it can calm and connect us, increase innovation and insight, and even heal what’s broken. We have a ‘blue mind’ — and it’s perfectly tailored to make us happy in all sorts of ways that go way beyond relaxing in the surf, listening to the murmur of a stream, or floating quietly in a pool.” – Wallace J. Nichols writes in Blue Mind: The Surprising Science That Shows How Being Near, In, On, or Under Water Can Make You Happier, Healthier, More Connected, and Better at What You Do, published in July 2014
Last Saturday, Greg Touliatos gave a great talk on water gardening. If you missed it, look for it on next year’s calendar of free classes. In the mean time, here are my thoughts, based upon Greg’s talk and his one page “Healthy Water Gardening Recipe.”
No garden is complete without a water feature of some sort. Water is life. Indeed, in nearly every description of gardens in literature, water figures prominently.
“A river went out of Eden to water the garden, and from there it parted and became four riverheads.” – Genesis 2:10
A healthy water garden is essentially a balanced, nearly self-contained, eco-system. If set up correctly, in the beginning, it can be very low maintenance, though not no-maintenance, for years to come. Everything works together.
First, a healthy population of beneficial bacteria is essential for any healthy pond. Beneficial bacteria chews up fish waste and debris that washes into the pond. It keeps odors down and turns many toxic substances into benign or even beneficial substances for pond plant life.
Because the size of your population of beneficial bacteria is a function of surface area, Greg recommends a layer of medium brown gravel for the bottom of your pond. Over-sized gravel has too much space between rocks. Also, it is difficult to walk on, if and when someone occasionally has to get into a pond to clean it or retrieve an item, like a baseball. Conversely, pea gravel packs down too tightly, defeating the point of gravel, which is to increase the quantity of surface space on the bottom of the pond for bacterial colonies to develop. Finally, medium sized gravel is relatively inexpensive, less than $50 per ton at the time of this writing. It can be supplemented for appearance purposes with more expensive rock, like Carolina Creek Rock or Mexican Beach Pebbles, but these products are too expensive and impractical to use as the main gravel for layering the bottom of a pond.
Build it and they will come? Maybe. Since we maintain good bacterial colonies in the pools we keep our fish and water plants in, it is likely that you will take some of those good bacteria home with you to your pond when you buy fish and plants from us. If you have set the stage with the right environment for bacteria to thrive in, with gravel and well-oxygenated water, chances are good they will find their way there. But, it is better to be sure.
Thus, Greg recommends two products for helping to maintain a healthy colony of beneficial bacteria, “Microbe Lift PL” and “Microbe Lift TAC.” He suggests ignoring the quantities in the instructions on the container (but not ignoring any safety instructions) and using what his experience has taught him is the correct approach, through trial and error.
Microbe Lift PL is a liquid, very stinky but very good. It comes with a measuring container in the box, about the size of a shot glass. Greg says use one shot glass per week, just dumping it directly into the water. If you have a UV light of some kind that you use as a part of your filtering/maintenance system, something Greg is not a big fan of, you need to turn it off for at least 72 hours after every application, or it is likely to just kill the bacteria.
Microbe Lift TAC is a powdered product, also filled with beneficial bacteria. Each jar comes with a small scoop and Greg says to add one scoop per day of this. If you don’t visit your pond every day, don’t let it become a burden. Just dump a scoop directly into the water every time you visit your pond, so long as you are also adding a shot glass of the Microbe Lift PL each week.
Second, make sure there are plenty of plants in the pond. Cover half to three quarters of the surface of the pond with plants to provide hiding places from predators for fish and reduce the prevalence of algae by cutting off sunlight intruding into the water. Reducing sunlight intruding into the pond water reduces algae.
There are four types of water plants to use in your pond: 1. Underwater oxygenating plants, like hornwort and purple cabomba; 2. Floating water plants, generally tropical and replaced yearly, like water hyacinth, sensitive plants, ludwegia, and water lettuce; 3. Water lilies, both hardy and/or tropical; and, 4. Marginal (shallow water) plants, like pickerel rush, powdery thalia, umbrella palm, equisetum (horsetail reed), and louisiana iris.
Third, use a product called Microbe lift Bio-Black, sparingly. I say “sparingly,” because a little goes a long way! Potent stuff.
Bio-Black is a liquid combination of pond colorant and enzymes. By tinting the water slightly, without making it opaque, sunlight penetration is reduced and, as I have already mentioned above, reducing sunlight reduces algae. According to the manufacturer and our experience, it: 1. will not stain birds, fish, pond rocks, or most concrete fountains once diluted; 2. is safe for humans, plants, and aquatic life; 3. safely colors water a reflective shade of black; 4. blocks out specific light rays that normally contribute to algae blooms; 5. digests organic waste; 6. reduces noxious odors; 7. does not necessitate restrictions on irrigation or fishing; and 8. Mixes completely in hours.
“Green water” is one of the biggest complaints we get from customers and clients. Green water is just algae, and Bio-Black is an important algae preventative measure. People like to be able to see your fish!
Fourth, circulate water with a high quality pump and filtration system. Make sure that your pump is continuous duty, i.e. not just made for short term use, and is of high quality, like the ones we currently carry that are made by Anjon. Although choosing a pump is a bit more complicated than this, a rule of thumb is that you want to circulate the water in the pond at least twice each hour. So, for example, if you have a 300 gallon water feature, you would want a pump that is rated at least 600 gallons per hour, minimum, with few exceptions.
Generally, pumps last longer if water is filtered before entering the pump. The best way to do this is to use a skimmer box with a filtering system built around the pump. The skimmer box, usually on the edge of the pond, allows the pond owner to access the pump without going into the pond and completely separates the pump from debris. It makes for fewer clogged pumps and easier maintenance.
But, installing a skimmer box, cutting the pond liner to fit around it and getting the skimmer box perfectly positioned, is better done by an experienced professional. So, if you have never constructed a pond with a skimmer box, you are better off placing the pump directly on the bottom of the pond. Sometimes, even pros choose to sit the pump directly on the bottom of the pond, if something about the site makes a skimmer box impractical. This can work with a good pre-filter, like our Matala Ez-Bio 11 and Ez-Bio 20 pre-filters. Debris can clog or at least slowly wear out pumps. Our highest grade of pumps, the Anjon Big Frogs, are said to be able to cut a golf ball into four pieces if one gets sucked through! But, it is best if it doesn’t have to do that.
If you use our Matala pre-filters, make the tubing between filter and pump as large as possible, use flexible tubing, make it long, and attach a piece of string or rope so that you can pull it up from the bottom if an when it appears blocked by accumulated debris. Small tubing, though tempting to use from an esthetics point of view, puts more strain on the pump and usually kinks easier, creating more problems all around.
So, bigger is usually better, within reason. Bigger capacity pumps get clogged less, last longer, and circulate the water more frequently. Bigger filtration systems reduce the particulate matter going through the pump so that it lasts longer. Bigger tubing, connecting pre-filter to pump and pump to outflow, means less clogging.
Many pumps, particularly the smaller pumps, come with a built-in but removable filtering device. In most cases, except perhaps in a fountain with no fish or plant matter and no trees to drop leaves in it, this built-in filter is inadequate and should be discarded and replaced with a better quality filtration system.
Fifth, use Microbe-Lift Aqua Xtreme when constructing a new water garden or changing water in or adding water to an existing water garden. According to Greg, “This product helps create a slime coat that protects your fish and fortifies water added to the pond.”
Sixth, every time you add a scoop of Microbe Lift TAC, toss in a pinch of pond salt. Pond salt also contributes to a healthy slime coat on your fish, reducing fish disease, but, additionally it helps settle out suspended particles, making your water less cloudy, and less hospitable to algae. According to Greg, it is “frankly a miracle for helping keep your pond right.” If you don’t do a pinch per day, at least do a handful or two per month.
‘Water that is too pure has no fish.” –Afghan Proverb
Finally, don’t be one of those people that demands perfectly clear water. Ponds are natural eco-systems, always in flux, filled with millions of organisms. I don’t know anyone from Afghanistan and I don’t know that Afghanis are particularly knowledgeable about water gardening, but, like many blog writers, I hunt for quotes to justify what I believe and I found a good one, a supposed Afghan proverb, floating (see what I did there?) around on the internet: “Water that is too pure has no fish.” Water gardens should not be cesspools but they are not swimming pools either.
Your crepe myrtles likely have a relatively new problem called crepe myrtle bark scale (CMBS). CMBS came over from Asia in a shipping container, possibly through Mexico, first arriving in Texas a few years ago. It has slowly moved East from there. The actual scale insects look like tiny pieces of puffed white rice. Though the male of the species is quite mobile, the female, which causes most of the problems, is relatively immobile, leaving us a little puzzled as to how the disease/pest spreads. Our thinking now is that it might spread by wind or birds but more likely spreads through mulch, bought in bulk from mulch yards, made of limbs and debris dumped at the mulch yard by landscapers, i.e. crepe myrtle bark pruning byproduct (think of the crepe murder that so many practice every year). Another possibility is that it gets on the clothing of landscapers themselves who travel from yard to yard. Regardless, it’s here!
The insect hurts the crepe myrtles in two ways. First, it feeds off of the tree, getting its nutrients from the outer cambium layer, depriving the tree of much needed nutrients, causing it to deteriorate. Second, it excretes a clear sticky substance, euphemistically called ‘honey dew,’ which becomes a perfect host for sooty mold, turning the tree black, coating the leaves and inhibiting photosynthesis, and often coating nearby plants too.
Currently, we are recommending a two-pronged approach, a systemic insecticide in the form of a soil drench, absorbed through the roots and moving throughout the tree, killing the insects when they feed on the tree. This is a slower but more thorough approach, slower because trees have a passive circulatory system and the substance is only pulled up through the tree as moisture transpires from the leaves during the night. The second prong is a contact pesticide or oil to provide a quicker knock-back, but a less complete kill. The important thing to remember is that a single pregnant female insect introduced on a crepe myrtle can have the entire tree covered in CMBS in just 2-3 weeks! So, act with a reasonable degree of haste.
We are currently recommending Fertilome Tree & Shrub Systemic Insect Drench (containing imidacloprid in a very high concentration) as the systemic, which may stay in the tree up to one year, combined with either horticultural oil or the liquid version of Sevin.
Environmental concerns: We prefer organic and natural approaches where possible, but there doesn’t seem to be an effective organic/natural control/kill for CMBS yet. Though this is debatable, with good arguments on both sides, we currently think the systemic, imidacloprid, despite being a neonic, has minimal impact on pollinators and other beneficial insects, because of the difficulty it has traveling into the flowers of the crepe myrtle. We do, however, caution that one should be cautious in using it near other plants that pollinators utilize, like perennial gardens. Additionally, we do know that any contact pesticide will kill any insect it comes in contact with. Therefore, out of respect for the benefits pollinators like butterflies, bees, etc., provide us, we urge you to only use the liquid Sevin, for example, closer to dark, when pollinators are less active. Finally, we urge that you consider cultural changes like switching to pine-straw mulch rather than wood mulch or at least getting the wood mulch in bag form, not planting crepe myrtles or removing and replacing the ones you already have with other trees, asking that your landscapers not come to your yard right after pruning infected crepe myrtles and making sure they are educated about the disease, making sure the trees are adequately watered and fertilized because we know that healthy trees are less attractive to harmful insects, etc.
Unfortunately, though we initially thought the CMBS species would limit itself to crepe myrtles, there is some evidence that it is attacking beauty berries, hawthornes, and maybe even other plants.
Each year, Greg Touliatos gives a seminar on this new disease and other pest problems. To learn more, check our facebook page or email us for a schedule of our free classes and attend them on Saturdays.
Caution! Don’t forget to read the label carefully and follow all procedures. The label is the law. Although we are told that imidacloprid is not easily absorbed transdermally, wear gloves and take other precautions necessary to keep it off of your skin and certainly keep it away from your face, i.e. not allowing it to splash as you are pouring. Further, remember that it is more harmful to pets than to humans. Therefore water it in heavily after applying it to the soil and keep your pets away until it has had a reasonable amount of time to sink below the surface.
When I first started as a landscape contractor, I loved hardwood mulch. The market rate for it, delivered and installed, was anywhere between $55 and $75 per cubic yard, with a 3-yard minimum. With landscaper discounts, I was able to get it for anywhere between $5 and $20 per cubic yard and the skill required to install it was not great, meaning that any properly motivated friend or recently unemployed person or teen, with 30 minutes training, could do it at a rate of about 3 cubic yards per hour. Properly shaken with a pitchfork, mulch provided a uniform appearance, covered up imperfections in the surface, blocked sunlight from penetrating to the dirt and promoting the germination of weed seed, and slowed the evaporation of moisture from the surface.
And, you should have heard my arguments for how beneficial it is for the environment! They were, of course, arguments I had heard elsewhere and believed. Mulch manufacturers take debris from cut-down trees, construction, and pruned limbs, etc., and grind it up until it has a uniform appearance. They sell it in bulk as a gardening product, rather than dumping it in a landfall, where it would degrade much more slowly.
Memphians love and like to pay for a fresh mulched yard. And, it creates jobs! How could one not love such a product?
I remembered growing up in my native South Carolina low country, where my stepfather and others would have me raking up “pine straw” (called pine needles by Memphians) to put in beds. After moving to Memphis, I found double-stamped “hardwood” mulch and could only pray that one day South Carolinians would discover it.
But, as they say, that was then and this is now. A decade later, after a few visits back to South Carolina and some careful reflection and listening to people like Caroline and Arthur Nave and Greg Touliatos, I now know why the azaleas, hydrangeas, camellias, and other plants are so much more beautiful along the Carolina and Georgia coast. It is likely, at least in part, because of pine straw.
But, what’s wrong with wood mulch? Well, a lot.
1. Wood mulch works best as a weed deterrent when it is in large chunks, but Memphians don’t like their wood mulch in big chunks any more than they like shredded pork sandwiches without slaw.They like their mulch at least double-stamped or even triple-stamped (referring to the number of times mulch is passed through a wood grinder). Though this mulch does prevent seeds below it from germinating, it is a perfect host for weed seeds dropped by birds. By having the wood more finely ground, they reduce its efficacy as a weed deterrent. (Memphians are right about barbecue, however. Theirs is much better than South Carolina’s.)
2. Wood mulch promotes termites. Every termite inspector I have met in Tennessee says that wood mulch should be kept at least 12 inches away from the foundation of a home, and some say it should be kept further away than that. Having recently taken a Tennessee chemical applicators licensing exam, I can tell you that official Tennessee guidelines for keeping termites at bay comport with this commonly held opinion. Listen to the experts. Termite damage is incredibly expensive and Memphis has the perfect climate for them.
But, I’ll just keep it 12 inches away from my house! Will you? With a tape measure? Won’t that look odd? Will you put down gravel in the 12 inch zone? Will the gravel mix with the dirt and the mulch? Do you expect the hourly summer employees of landscape companies to keep it exactly 12 inches from your house? Do you trust your spouse to get this right? Your teens? What happens if you pay to have your home treated for termites and your termite company points to a clause in their indemnity contract about wood mulch being too close to the home, and it turns out you missed a spot where a little was up against the foundation? Will they still honor the indemnity agreement.
But, I’ll just use cypress, or cedar, or redwood mulch and it will keep the termites away! Hardly. Mulches are rarely as pure as they are labeled. It is expensive and difficult to keep the types of wood used for mulch entirely separate. Most suppliers can, at best, warrant that it is mostly one type of wood. Second, opinions (the legitimate ones that count) vary about the degree to which these woods really repel termites. We know, for example, that only old-growth cypress heartwood has the resins in it that repel bugs, and there isn’t much old-growth cypress left in the United States. And, if we keep cutting down young-growth cypress, there won’t be any old-growth cypress, eventually. Remember the vague, pro-environmental, recycling argument I used above? If you use one of these kinds of mulches, you can pretty much forget that argument.
3. Wood mulch competes with your plants for nitrogen. This is because all organic matter, in its early stages of decomposition, is nitrogen robbing, only releasing the nitrogen back into the environment late in the process of decomposition. So, either you have to put down more fertilizer or you will see a slowing of new canopy growth, and a reduction in the plant’s ability to shake disease. One might rightly point out that pine straw is also organic matter and is also nitrogen-robbing in its early stages of decomposition, but, pine straw is far less dense. The nitrogen-robbing effect of hardwood mulch is exponentially greater than with pine straw.
4. The wood used in wood mulch didn’t end up in the mulch pile because someone made a great sacrifice. It ended up there because someone wanted it gone. And, very often, though not always, they wanted it gone because it was infected with a pathogen of some kind.
I used to tell my customers, “Oh, don’t worry. Because it’s in big piles and gets so hot, all the bad stuff gets cooked out.” Maybe, sort of, sometimes. (In my defense, I honestly believed that to be true for many years.) Consider, for example, the recent widespread spread of crepe/crape myrtle bark scale in the Mid-south. As Greg Touliatos has rightly pointed out, since the female of the species only moves a short distance in her entire life, a distance measured in inches, at most, we have to ask, how is it spreading? Could it be wind? Birds? Maybe, but it is still spreading awfully fast for that to be the only source of transport. The more likely explanation is landscapers and the wood mulch from mulch yards, bought in bulk. Can Greg prove that assertion? Not without a lot of time and money, but I regard it as probable, and you would be wise to do so, as well, until more data and a good competing explanation is presented.
I suppose landscapers could change clothes and sanitize all of their equipment between yards, and pre-treat your wood mulch, but what consumer is willing to pay for that?
5. Wood mulch is heavy; unless you buy it in bags, you must transport it with a pickup or dump truck or pay someone else to deliver it. And, if you buy it in bags, you have to pay a lot more. In contrast, my source (read: the google) says the average bale of pine straw weighs less than 12 pounds. No wheel barrow or pitchfork required. Gloves are advised, but not strictly necessary.
6. If wood mulch is piled against the trunks of woody plants it promotes damage to the outer cambium layer, the thin outer ring of recent growth. It is the main, in some cases, the only highway for nutrients to move up and down the trunk of a plant. If this layer is damaged and/or rendered non-working, the plant dies, every time.
Wood mulch holds water, like a sponge, and, though the roots of plants absorb and utilize moisture very well, the trunk wood does not. Although good landscapers and gardeners know to keep the wood mulch off of trunks, this is not done as often as it should be. And, heavy rains can move mulch, leaving it in drifts piled up against trunks, even if the person who originally installed the mulch did so with great attention to this detail.
7. Bulk mulch can have a ph problem. Ph is the measure of alkalinity/acidity, the middle of the scale being 7 and most plants thriving at various points along the ph scale between 5.5 and 7.5. Anything below 7 is regarded as acidic and anything above that number is considered alkaline. Once, early in my career, I bought 20 cubic yards of wood mulch and had it delivered by dump truck from a mulch yard to a property owned by two scientists in Cordova. They were new clients, with willingness and ability to pay, so, I was not only pleased to be making the profit from the mulch install but also hoping for more business from them in years to come. The next day, all of the perennials they’d recently planted, several hundred dollars worth — perennials that were in perfectly good shape when I arrived on the scene — were all in a wilted and browned-out state. Saying they were annoyed was an understatement.
How could this be my fault? My assistant promised he had heavily watered it in to counter any moisture robbing effects. And, we had done a nice underlayment of composted leaf mulch to counter any nitrogen-robbing effect. I denied any wrong-doing on my part. But they, being scientists, tested the mulch’s ph and said that it was under 4 in nearly every spot — highly acidic — and, smelled like rotten eggs.
So, I began to research. Turns out that mulch not turned regularly at the mulch yard, though it cooks out many pathogens, promotes anaerobic organisms. Anaerobic organisms excrete compounds that are highly acidic and toxic to plants. Further, the excretions give off a rotten egg smell.
It cost hundreds of dollars to replace their perennials and I never again received any business or referrals from them.
Now, the supplier of mulch Urban Earth uses is very conscientious about this issue and, even if they weren’t, our mulch sits for some time in a smaller pile after transport to our garden center before being sold, allowing it to air out and get access to oxygen.
Even after I have explained all of this to my customers at Urban Earth, I still sometimes hear two arguments: 1) I’m sure pinestraw carries diseases too. 2) Your pine straw costs $9 per bale and I can get hardwood mulch for less than $5 per bag, and even cheaper by the truckload.
Let’s address these in reverse order. Depending on density of plant matter in your beds and how thick you put it on, the pine straw covers anywhere from 20 square feet to 50 square feet, with 30 square feet being about the median coverage factor, in my experience. Wood mulch covers about 10 square feet per bag. That means customers end up paying between 18 cents and 45 cents per square foot for pine straw and 25 cents to 50 cents for bagged wood mulch. So, if anything, pine straw is cheaper.
As for the disease argument, it is possible for anything to carry disease, but it is far less likely that pine straw will and, even if it does, it is less likely that the particular disease will effect your plants. Pine needles are shed by trees naturally and regularly. Even if the source pine tree is diseased, most diseases are pretty specific to a plant. So, unless you’re using it to mulch around other pines or closely related species, you’re in the clear.
So, there are a few things to learn from this. First, hardwood mulch is for chumps and you should stop using it. Second, the advice I give you may later turn out to be terrible and it does not offend me in the least if you double check it with other sources, including soliciting competing opinions from other staff at Urban Earth. Third, I am willing to admit I was wrong and I owe all of my old clients from my days as a landscape contractor an apology (but don’t try to get any money out of me). Fourth, Urban Earth carries bales of pine straw and you should buy from us when you need it. Fifth, Urban Earth also carries double-stamped wood mulch in bulk, sold by the cubic yard, but will likely discontinue carrying wood mulch in bags once our current supply runs out.
Unless our customers decide I don’t know what I’m talking about and continue to demand it.
— John Jennings, Manager